Objective To analyze the risk factors for duration of mechanical ventilation in critically ill patients. Methods Ninety-six patients who received mechanical ventilation from January 2011 to December 2011 in intensive care unit were recruited in the study. The clinical data were collected retrospectively including the general condition, underlying diseases, vital signs before ventilation, laboratory examination, and APACHEⅡ score of the patients, etc. According to ventilation time, the patients were divided into a long-term group ( n = 41) and a short-term group ( n = 55) . Risk factors were screened by univariate analysis, then analyzed by logistic regression method.Results Univariate analysis revealed that the differences of temperature, respiratory index, PaCO2 , white blood cell count ( WBC) , plasma albumin ( ALB) , blood urea nitrogen ( BUN) , pulmonary artery wedge pressure ( PAWP) , APACHEⅡ, sex, lung infection in X-ray, abdominal distention, and complications between two groups were significant.With logistic multiple regression analysis, the lower level of ALB, higher level of PAWP, lung infection in X-ray, APACHE Ⅱ score, abdominal distention, and complications were independent predictors of long-term mechanical ventilation ( P lt;0. 05) . Conclusion Early improving the nutritional status and cardiac function, control infection effectively, keep stool patency, and avoid complications may shorten the duration of mechanical ventilation in critically ill patients.
Objective To compare the humidification effect of the MR410 humidification system and MR850 humidification system in the process of mechanical ventilation. Methods Sixty-nine patients underwent mechanical ventilation were recruited and randomly assigned to a MR850 group and a MR410 group. The temperature and relative humidity at sites where tracheal intubation or incision, the absolute humidity, the sticky degree of sputum in initial three days after admission were measured. Meanwhile the number of ventilator alarms related to sputum clogging and pipeline water, incidence of ventilator associated pneumonia, duration of mechanical ventilation, and mortality were recorded. Results In the MR850 group,the temperature of inhaled gas was ( 36. 97 ±1. 57) ℃, relative humidity was ( 98. 35 ±1. 32) % , absolute humidity was ( 43. 66 ±1. 15) mg H2O/L, which were more closer to the optimal inhaled gas for human body.The MR850 humidification system was superior to the MR410 humidification system with thinner airway secretions, less pipeline water, fewer ventilator alarms, and shorter duration of mechanical ventilation. There was no significant difference in mortality between two groups. Conclusions Compared with MR410 humidification system, MR850 humidification system is more able to provide better artificial airway humidification and better clinical effect.
Objective To study polyuria during mechanical ventilation in patients with chronic obstructive pulmonary disease ( COPD) and its possible mechanisms. Methods The plasma and urine concentrations of cystatin C ( CyC) were measured by enzyme immunometric assay in 26 COPD patients who received mechanical ventilation at timepoints of 0 h, 24 h, 48 h, 72 h and 1 week. And plasma levels of atrial natriuretic factor ( ANF ) , antidiuretic hormone ( ADH) and aldosterone ( ALD) were detected byradioimmunoassay at the same time-point. The urine volume was recorded every day. The samples of 30 healthy volunteers were measured as control. Results Polyuria phenomenon was found in majority of patients in 24 to 72 hours after mechanical ventilation. At 0h, the concentrations of plasma CyC, urine CyC,plasma ANF, ADH and ALD were all increased significantly compared with those of the control, respectively [ ( 4. 87 ±0. 51) mg/L vs ( 1. 29 ±0. 27) mg/L, ( 0. 58 ±0. 13) mg/L vs ( 0. 07 ±0. 02) mg/L, ( 37. 02 ±4. 35) pmol /L vs ( 22. 51 ±1. 18) pmol /L, ( 8. 61 ±1. 43) pmol /L vs ( 0.94 ±0. 34) pmol /L, ( 925. 4 ±142. 7) pmol /L vs ( 297. 5 ±135. 8) pmol /L, all P lt; 0. 01] , then decreased gradually after mechanical ventilation. The levels of plasma CyC and ANF at 24 h, plasma ADH at 72 h, and urine CyC at 1 week were similar to those of the control( all P gt;0. 05) , respectively, except the level of plasma ALD was still higher by 1 week( P lt; 0. 05) . Conclusions Polyuria is not a rare phenomenon for COPD patients receiving mechanical ventilation. Polyuria is related to the readjustment and mal-adaptation of ADH and reninangiotensin-aldosterone-systems during mechanical ventilation.
Objective To analyze the clinical features and treatment of severe H1N1 influenza.Methods The clinical data of 34 patients with severe H1N1 influenza admitted to intensive care unit from October to December 2009 were reviewed. Results The patients aged 3 months to 60 years with an average of ( 13. 9 ±4. 5) years, of which 24 patients were younger than 7 years old. Fever( 30 cases) , cough( 32 cases) , progressive shortness of breath( 19 cases) were the main symptoms. White blood cell count was normal in 21 cases, increased in 6 cases, and decreased in 7 cases. Lymphocyte count was normal in 16 cases, increased in 12 cases, and decreased in6 cases. Chest X-ray films showed bilateral or unilateral patchy pulmonary fuzzy shadows in28 cases. Chest CT showed diffuse interstitial lesion in1 case, pleural effusion in 2 cases, and bronchiectasis in 1 case. The hepatic and myocardial enzymogramparameters were all abnormal.30 cases were treated by oseltamivir and ribavirin, 4 cases by methyllprednisolone, and 6 cases by gamma globulin. 8 cases underwent routine intubation and mechanical ventilation, and 5 cases received non-invasive mechanical ventilation. All 34 patients were cured. Conclusions Lung, heart, and liver are the major target organs in severe H1N1 influenza. Mechanical ventilatory support is an important treatment for severe H1N1influenza.
ObjectiveTo compare the indirect calorimetry (IC) measured resting energy expenditure (MREE) with adjusted Harris-Benedict formula calculating resting energy expenditure (CREE) in the mechanically ventilated surgical critically ill patients and to evaluate the relationship between the resting energy expenditure (REE) with the severity of illness. MethodsTwenty-one patients undergonging mechanical ventilation for critical illness in the intensive care unit of general surgery between August 2008 and February 2010 were included in this study. Data during the study period of nutrition support were collected for computation of the severity of critical illness by acute physiology and chronic health evaluation Ⅱ scores (APACHE Ⅱ scores) and organ dysfunction scores (Marshall scores). MREE was measured by using IC of the MedGraphics CCM/D System within the first 7 d after nutrition therapy. CREE was calculated by using the HarrisBenedict formula adjusted with correction factors for illness at the same time. According to APACHE Ⅱ scores on admission, the enrolled patients were divided into two groups: APACHEⅡ score ≥20 scores group (n=8) and APACHE Ⅱ score lt;20 scores group (n=13), and the differences between MREE and CREE of patients in two groups were determined. ResultsThe reduction of variation tendency in CREE other than MREE in the enrolled patients within the first week of nutritional support was statistical significance (Plt;0.001). The CREE of patients 〔(1 984.49±461.83) kcal/d〕 was significantly higher than the MREE 〔(1 563.88±496.93) kcal/d〕 during the first week of nutritional support (Plt;0.001). The MREE on the 0, 1, 2, and 4 d after nutrition therapy were statistically significant lower than CREE at the same time interval in these patients (Plt;0.01), and the differences at the other time points were not significant (Pgt;0.05). There was a trend towards a reduction in APACHE Ⅱ and Marshall scores within the first week of nutrition therapy that reached statistical significance (Plt;0.001). During the first week of nutrition therapy, APACHEⅡ and Marshall scores of patients in ≥20 scores group were significantly higher than those in lt;20 scores group, respectively (Plt;0.05 or Plt;0.01), and the reductions of APACHE Ⅱ scores and Marshall scores were significant in patients of two groups (Plt;0.001). A significant positive correlation was found between CREE with APACHE Ⅱ scores (r=0.656, Plt;0.001) and Marshall scores (r=0.608，Plt;0.001) in patients within the first week after nutrition support. Although no statistically significant correlation was observed between MREE and APACHEⅡ scores (r=-0.045， P=0.563), a significant positive correlation was observed between MREE and Marshall scores (r=0.263, P=0.001) within the first week after nutrition therapy. There was no correlation between MREE and CREE (r=0.064, P=0.408) in patients at the same time interval. The reduction of MREE of patients in ≥20 scores group other than in lt;20 scores group was statistically significant within the first week after nutrition therapy (P=0.034). In addition, the MREE of patients in ≥20 scores group were not significantly different from those in lt;20 scores group (Pgt;0.05), and the mean CREE was not different in two groups patients within the first week of nutritional therapy 〔(1 999.55±372.73) kcal/d vs. (1 918.39±375.27) kcal/d, P=0.887〕. CREE was significantly higher than MREE of patients in ≥20 scores group within the first week except the 3 d and 5 d after nutrition therapy (Plt;0.05), while in lt;20 scores group CREE was significantly higher than MREE in patients only within the first 3 d after nutrition therapy (Plt;0.05 or Plt;0.01). MREE and CREE of patients in ≥20 scores group were not different from those in lt;20 scores group, respectively (Pgt;0.05).
Objective To analyze the relationship between end-tidal carbon dioxide partial pressure (PETCO2) and arterial CO2 pressure (PaCO2) in invasive ventilated patients. Methods An observational study was conducted in adult patients admitted to Intensive Care Unit (ICU) between June 2016 and March 2017. Samples were immediately analyzed for PaCO2 using a blood gas analyzer. At the same time the arterial to end-tidal CO2 gradient was determined. Relationship in different mechanical ventilation modes, disease categories and PaO2/FiO2 were analyzed in this study. Results A total of 225 arterial blood gases were obtained from the 104 patients. In each of these modes the PETCO2 was generally lower than the PaCO2. There was a positive correlation between PaCO2 and PETCO2 regardless of different mode (r=0.70, Y=11.08+0.77X). A positive correlation was found in SIMV and SPONT modes, but not in A/C mode. The relationship between PaCO2 and PETCO2 in COPD, trauma, cerebrovascular disease and severe pneumonia patients shown a positive correlation (r value was 0.76, 0.64, 0.53, and 0.56, respectively). There was a significant correlation whether PaCO2/FiO2<200 mm Hg (r=0.69, P<0.001) or ≥200 mm Hg (r=0.71, P<0.001). Conclusions The results of this study show that PETCO2 monitoring accurately reflects PaCO2 during mechanical ventilation. A positive correlation is found in different ventilation modes, regardless of disease categories or PaCO2/FiO2.
ObjectiveTo evaluate the predictive value of diaphragmatic rapid shallow breathing index (D-RSBI) for weaning outcome prediction.MethodsThis was a prospective observation study. Respiratory rate (RR) and tidal volume (Vt) were recorded at the end of spontaneous breathing trial, and both M-Mode and B-Mode ultrasonography were used to assess the right diaphragmatic displacement (DD). In parallel, outcome of the weaning attempt, length of mechanical ventilation, length of stay in intensive care unit (ICU) and mortality of ICU were recorded. According to the weaning outcome, the patients were grouped into the successful group and the failed group. The receiver operator characteristic (ROC) curve was used to assess the value of rapid shallow breathing index (RSBI, RR/Vt) and D-RSBI (RR/DD) in predicting weaning failure for ICU patients with mechanical ventilation.ResultsA total of 110 patients recruited in this study. Of them, 73 (66.4%) patients were successfully liberated from mechanical ventilation, and 37 patients failed (33.6%) weaning procedure. The RSBI and D-RSBI of the patients in the failed group were higher than those in the success weaning group (P<0.01). The area under the ROC curves of RSBI and D-RSBI for predicting weaning failure was 0.78 (95% confidence interval 0.69 - 0.87), 0.91 (95% confidence interval 0.85 - 0.97), respectively, a cutoff of RSBI>69 breaths/(L·min) yielded sensitivity of 55% and specificity of 89%, and a cutoff of D-RSBI>1.5 breaths/(min·mm) yielded sensitivity of 87% and specificity of 80%.ConclusionD-RSBI is more accurate than traditional RSBI in predicting the weaning outcome.
Objective To assess the risk factors associated with extubation failure in patients who had successfully passed a spontaneous breathing trial.Methods Patients receiving invasive mechanical ventilation for over 48 h were enrolled in the study，they were admitted into Emergency ICU of Zhongshan Hospital during May 2006 and Oct.2007.A spontaneous breathing trial was conducted by a pressure support of 7 cm H2O for 30 min.Clinical data were prospectively recorded for the patient receiving full ventilatory support before and after the spontaneous breathing trial.Regarding the extubation outcome，patients were divived into extubation success group and extubation failure group.Results A total of 58 patients with a mean（±SD） age of 69.4±12.7 years passed spontaneous breathing trial and were extubated.Extubation failure occurred in 11 patients（19%）.The univariate analysis indicated the following associations with extubation failure：elderly patients（78.1±7.9 years vs 67.4±15.1years，Plt;0.05），higher rapid shallow breathing index（RSBI） value（83±12 breaths·min-1·L-1 vs 68±19 breaths·min-1·L-1，Plt;0.05）and excessive respiratory tract secretions（54.5％ vs 21.3％，Plt;0.05）.Conclusion Among routinely measured clinical variables，elderly patients，higher RSBI value and amount of respiratory tract secretions were the valuable index for predicting extubation failure despite a successful spontaneous breathing trial.
ObjectiveTo investigate the clinical value of peripheral blood vitamin D level in predicting the outcome of weaning from mechanical ventilation in critically ill patients.MethodsA total of 130 critically ill patients who undergoing mechanical ventilation for more than 48 hours in our hospital were recruited from June 2014 to June 2017. Serum 25(OH)D3 was detected on admission and before spontaneous breathing test (SBT) meanwhile general clinical data and laboratory examination indexes were recorded. The cases were divided into a successful weaning group and a failure weaning group according to the outcome of weaning from mechanical ventilation. Logistic regression equation was used to analyze the relationship between vitamin D level and failure weaning, and a receiver operating characteristic (ROC) curve was used to analyze the predictive value for failure weaning.ResultsThere were 46 patients with failure weaning among 130 patients (35.38%). Compared with the successful weaning group, the failure weaning group had significantly higher Acute Physiology and Chronic Health EvaluationⅡ score, longer duration in intensive care unit, higher respiratory rate, higher rapid shallow breathing index, higher C-reactive protein, higher N-terminal prohormone of brain natriuretic peptide, higher serum creatinine, and significantly lower albumin (all P<0.05). 25(OH)D3 level classifications on admission and before SBT in the failure weaning group were worse than those in the successful weaning group (P<0.05). 25(OH)D3 levels of the failure weaning group were lower than those of the successful weaning group [on admission: (18.16±4.33) ng/ml vs. (21.60±5.25) ng/ml, P<0.05; before SBT: (13.50±3.52) ng/mlvs. (18.61±4.30) ng/ml, P<0.05]. Multivariate logistic regression analysis showed that 25(OH)D3 levels on admission and before SBT were independent risk factors for failure weaning (OR values were 2.257 and 2.613, respectively, both P<0.05). ROC curve analysis showed that areas under ROC curve were 0.772 and 0.836, respectively, with sensitivities of 80.3% and 85.2%, specificities of 69.0% and 71.0%, respectively.Conclusions25(OH)D3 deficiency or insufficiency is common in critically ill patients. The lower the level of vitamin D, the higher the risk of failure weaning. So it may be an independent predictor of failure weaning.
ObjectiveTo investigate the condensate pollution in the pipeline of severe pneumonia patients undergoing mechanical ventilation.MethodsFrom January 2017 to January 2019, 120 patients with severe pneumonia treated by mechanical ventilation in our hospital were collected continuously. The lower respiratory tract secretions were collected for bacteriological examination. At the same time, the condensed water in the ventilator exhaust pipe was collected for bacteriological examination at 4, 8, 12, 16, 20 and 24 hours after tracheal intubation and mechanical ventilation. The bacterial contamination in the condensed water at different time points was analyzed and separated from the lower respiratory tract. The consistency of bacteria in secretion and drug resistance analysis of bacterial contamination in condensate water were carried out.ResultsOf the 120 patients with severe pneumonia after mechanical ventilation, isolates were cultured in the lower respiratory tract secretions of 102 patients. One strain was cultured in 88 cases, two strains were cultured in 10 cases, and three strains were cultured in 4 cases. The isolates were mainly Gram-negative bacteria (57.5%) and Gram-positive bacteria (42.5%). The most common isolates were Pseudomonas aeruginosa, Staphylococcus aureus and Acinetobacter baumannii. The contamination rate of condensate water was 5.0% at 4 hours, 37.5% at 8 hours, 60.0% at 12 hours, 76.7% at 16 hours, 95.0% at 20 hours, and 100.0% at 24 hours, respectively. The bacterial contamination rate in condensate water at different time points was statistically significant (P=0.000). The pollution rate at 4 hours was significantly lower than that at 8 hours (P=0.000). Gram-negative bacteria accounted for 57.5% and Gram-positive bacteria accounted for 42.5%. The most common isolates were Staphylococcus aureus, Pseudomonas aeruginosa and Acinetobacter baumannii. The consistency of bacteria in lower respiratory tract and condensate water was 83.3% in severe pneumonia patients undergoing mechanical ventilation. The overall resistance of Pseudomonas aeruginosa, Acinetobacter baumannii and Staphylococcus aureus was higher, but the resistance to imipenem/cilastatin was lower.ConclusionsThe bacterial contamination in the condensate of patients with severe pneumonia during mechanical ventilation is serious. The pollution rate is low within 4 hours. It is consistent with the bacterial contamination in lower respiratory tract and the bacterial resistance is high.